2,768 research outputs found
Early versus late initiation of GH replacement in adult-onset hypopituitarism
Introduction: Adult-onset growth hormone deficiency (AGHD) is usually the last deficiency to be substituted in hypopituitarism. In children with documented GH deficiency, treatment without delay is crucial for achieving optimal effects on growth and development. In adults, it is not known whether a delay in treatment initiation influences biochemical response and the favourable physiological effects resulting from GH replacement therapy (GHRT). Methods: A total of 1085 GH-deficient adults from KIMS (Pfizer International Metabolic Database) were included, adequately replaced with all pituitary hormones except for GH at baseline. Patients were stratified by sex and age (20–50 years and ≥50 years) and subsequently divided into two groups below and above the median duration of unsubstituted AGHD for that subgroup. The median time of unsubstituted GHD for the total cohort was 2.53 years (P5 = 0.35, P95 = 24.42). Results: Beneficial effects of 4 years of GHRT were observed on lipids and quality of life iall subgroups. A decrease in waist circumference was observed only in older (>50 years) patients. There was no difference in IGF-I SDS and in GH dose required to normalize IGF-I in patients with a duration of unsubstituted AGHD above or below the median. No relevant differences were found between the groups for anthropometric measures, cardiovascular risk factors and quality of life scores. Conclusion: In contrast to GHD in children and adolescents, no difference could be established in treatment response between early or late initiation of GHRT in AGHD in terms of required GH dose, IGF-I, metabolic health and quality of life
Longevity of supersymmetric flat directions
We examine the fate of supersymmetric flat directions. We argue that the
non-perturbative decay of the flat direction via preheating is an unlikely
event. In order to address this issue, first we identify the physical degrees
of freedom and their masses in presence of a large flat direction VEV (Vacuum
Expectation Value). We explicitly show that the (complex) flat direction and
its fermionic partner are the only light {\it physical} fields in the spectrum.
If the flat direction VEV is much larger than the weak scale, and it has a
rotational motion, there will be no resonant particle production at all. The
case of multiple flat directions is more involved. We illustrate that in many
cases of physical interest, the situation becomes effectively the same as that
of a single flat direction, or collection of independent single directions. In
such cases preheating is not relevant. In an absence of a fast non-perturbative
decay, the flat direction survives long enough to affect thermalization in
supersymmetric models as described in hep-ph/0505050 and hep-ph/0512227. It can
also ``terminate'' an early stage of non-perturbative inflaton decay as
discussed in hep-ph/0603244.Comment: 9 revtex pages, v3: expanded discussion on two flat directions, minor
modifications, conclusions unchange
Health-economic evaluation of meniscus tear treatments:a systematic review
Purpose: To evaluate the overall evidence of published health-economic evaluation studies on meniscus tear treatment.Methods: Our systematic review focuses on health-economic evaluation studies of meniscus tear treatment interventions found in PubMed and Embase databases. A qualitative, descriptive approach was used to analyze the studies’ results and systematically report them following PRISMA guidelines. The health-economic evaluation method for each included study was categorized following one of the four approaches: partial economic evaluation (PEE), cost-effectiveness analysis (CEA), cost–benefit analysis (CBA), or cost-utility analysis (CUA). The quality of each included study was assessed using the Consensus on Health Economic Criteria (CHEC) list. Comparisons of input variables and outcomes were made, if applicable.Results: Sixteen studies were included; of these, six studies performed PEE, seven studies CUA, two studies CEA, and one study combined CBA, CUA, and CEA. The following economic comparisons were analyzed and showed the respective comparative outcomes: (1) meniscus repair was more cost-effective than arthroscopic partial meniscectomy (meniscectomy) for reparable meniscus tear; (2) non-operative treatment or physical therapy was less costly than meniscectomy for degenerative meniscus tear; (3) physical therapy with delayed meniscectomy was more cost-effective than early meniscectomy for meniscus tear with knee osteoarthritis; (4) meniscectomy without physical therapy was less costly than meniscectomy with physical therapy; (5) meniscectomy was more cost-effective than either meniscus allograft transplantation or meniscus scaffold procedure; (6) the conventional arthroscopic instrument cost was lower than laser-assisted arthroscopy in meniscectomy procedures.Conclusion: Results from this review suggest that meniscus repair is the most cost-effective intervention for reparable meniscus tears. Physical therapy followed by delayed meniscectomy is the most cost-effective intervention for degenerative meniscus tears. Meniscus scaffold should be avoided, especially when implemented on a large scale.Level of evidence: Systematic review of level IV studies.</p
Neutron Resonance Spectroscopy of 106Pd, and 108Pd from 20–2000 eV
Parity nonconserving asymmetries have been measured in p-wave resonances of 106Pd and 108Pd. The data analysis requires knowledge of the neutron resonance parameters. Transmission and capture γ-ray yields were measured for En=20–2000 eV with the time-of-flight method at the Los Alamos Neutron Science Center (LANSCE). A total of 28 resonances in 106Pd and 32 resonances in 108Pd were studied. The resonance parameters for 106Pd are new for all except one resonance. In 108Pd six new resonances were observed and the precision improved for many of the resonance parameters. A Bayesian analysis was used to assign orbital angular momentum for the resonances studied
The Robustness of n_s < 0.95 in Racetrack Inflation
A spectral index n_s < 0.95 appears to be a generic prediction of racetrack
inflation models. Reducing a general racetrack model to a single-field
inflation model with a simple potential, we obtain an analytic expression for
the spectral index, which explains this result. By considering the limits of
validity of the derivation, possible ways to achieve higher values of the
spectral index are described, although these require further fine-tuning of the
potential.Comment: 7 pages, 2 figure
Quantized Adiabatic Charge Transport in a Carbon Nanotube
The coupling of a metallic Carbon nanotube to a surface acoustic wave (SAW)
is proposed as a vehicle to realize quantized adiabatic charge transport in a
Luttinger liquid system. We demonstrate that electron backscattering by a
periodic SAW potential, which results in miniband formation, can be achieved at
energies near the Fermi level. Electron interaction, treated in a Luttinger
liquid framework, is shown to enhance minigaps and thereby improve current
quantization. Quantized SAW induced current, as a function of electron density,
changes sign at half-filling.Comment: 5 pages, 2 figure
Parity Nonconservation in 106Pd and 108Pd Neutron Resonances
Parity nonconservation (PNC) has been studied in the neutron p-wave resonances of 106Pd and 108Pd in the energy range of 20 to 2000 eV. Longitudinal asymmetries in p-wave capture cross sections are measured using longitudinally polarized neutrons incident on ∼20-g metal-powder targets at LANSCE. A CsI γ-ray detector array measures capture cross section asymmetries as a function of neutron energy which is determined by the neutron time-of-flight method. A total of 21 p-wave resonances in 106Pd and 21 p-wave resonances in 108Pd were studied. One statistically significant PNC effect was observed in106Pd, and no effects were observed in 108Pd. For 106Pd a weak spreading width of Γw=34-28+47×10-7 eV was obtained. For 108Pd an upper limit on the weak spreading width of Γw\u3c12×10-7 eV was determined at the 68% confidence level
Parity Violation in Neutron Resonances in 107,109Ag
Parity nonconservation (PNC) was studied in p-wave resonances in Ag by measuring the helicity dependence of the neutron total cross section. Transmission measurements on natural Ag were performed in the energy range 32 to 422 eV with the time-of-flight method at the Manuel Lujan Neutron Scattering Center at Los Alamos National Laboratory. A total of 15 p-wave neutron resonances were studied in 107Ag and ninep-wave resonances in 109Ag. Statistically significant asymmetries were observed for eight resonances in 107Ag and for four resonances in109Ag. An analysis treating the PNC matrix elements as random variables yields a weak spreading width of Γw=(2.67-1.21+2.65)×10-7 eV for107Ag and Γw=(1.30-0.74+2.49)×10-7 eV for 109Ag
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